Upgrade to 3.0.2

kirby/src/Cms/Page.php

@@ -608,10 +608,19 @@ class Page extends ModelWithContent
     /**
      * Checks if the page is a descendant of the given page
      *
+     * @param string|Page $parent
      * @return boolean
      */
-    public function isDescendantOf(Page $parent): bool
+    public function isDescendantOf($parent): bool
     {
+        if (is_string($parent) === true) {
+            $parent = $this->site()->find($parent);
+        }
+
+        if (!$parent) {
+            return false;
+        }
+
         return $this->parents()->has($parent->id()) === true;
     }
 
@@ -828,7 +837,7 @@ class Page extends ModelWithContent
      * @param string|null $handler
      * @return int|string
      */
-    public function modified(string $format = 'U', string $handler = null)
+    public function modified(string $format = null, string $handler = null)
     {
         return F::modified($this->contentFile(), $format, $handler ?? $this->kirby()->option('date.handler', 'date'));
     }